Paul contradicting Yahweh : Was Abraham chosen because of his Faith or His obedience?

Paul contradicting Yahweh:

Genesis 26:4-5 And I will make thy seed to multiply as the stars of heaven, and will give unto thy seed all these countries; and in thy seed shall all the nations of the earth be blessed; Because that Abraham obeyed my voice, and kept my charge, my commandments, my statutes, and my laws.”

“because that Abraham…kept…my law” – YAHWEH

Romans 4:13 For the promise, that he should be the heir of the world, [was] not to Abraham, or to his seed,through the law, but through the righteousness of faith.